| 摘要 |
1,188,382. Turbine and like blades. GENERAL ELECTRIC CO. May 5, 1967, No.21134/67. Heading F1T. A cooled turbine or like vane comprises a hollow body formed with a plenum chamber having a heat transfer fluid inlet and throttling means for directing the heat transfer fluid against the interior wall of the chamber in the leading edge region of the vane body, and a multiplicity of passages in the leading edge region for inter-connecting the plenum chamber and the exterior wall, the passages being disposed along axes forming acute angles with the plenum chamber walls to discharge the fluid from the chamber in a relatively thin layer over the exterior wall in the leading edge region of the vane body. The invention is described with reference to a vane of an annular nozzle diaphragm of a gas turbine but is equally applicable to the construction of other blades and to vanes used in either high temperature turbomachines, such as high-pressure compressors. The vane body 33 is an aerofoil shaped member, the plenum chamber of which is divided into two regions 50, 51 by a radial partition 52. A serpentine passage is formed downstream of the region 51 by radial partitions 57, 58 dividing the interior of the vane body 33 into two radial passages 60, 61. The partitions 57, 58 not quite extend to the inner base 34 and outer end plate (not shown) respectively so as to form openings 62, 63. Relatively cool compressed air for cooling the vane body 33 is bled from an annular chamber which surrounds the combustion space of the gas turbine and admitted through inlet 55, filling the plenum region 51 and flowing through throttling openings 74 in the partition 52 into the region 50. Rows of radially spaced, small diameter passages 70 a, b, c, in the leading edge region connect the region 50 with the convex side wall surface 45, the concave side wall surface 46, and the leading edge 47 respectively. The axes of the passages 70a, b connecting with the convex and concave surfaces from an acute angle, preferably less than 30 degrees, with these surfaces so that the cooling fluid is discharged axially downstream along the surfaces toward the trailing edge 48. The axes of the remaining passages 70c form an angle of approximately 45 degrees with the leading edge 47 so that the cooling fluid is discharged radially outward along the leading edge 47. Compressed air also enters the serpentine passage through the opening 62, providing convection cooling in the midchord region where the film of cooling fluid begins to separate from the convex and concave side wall surfaces. Convection cooling is provided in the trailing edge region by cooling fluid flowing through small diameter passages 72 extending axially between the radial passage 61 and the trailing edge 48. The convection cooling in the leading edge region is supplemented by boundary layer cooling, the cooling fluid discharged by the passages 70 being trapped in the boundary layer, thus insulating the vane body 33 from the hot combustion products. |
